Canon Patent: RF 80-240mm f/3.5 Zoom Lens For EOS R System

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Here is another Canon patent application. This one is for a RF 80-240mm f/3.5 zoom lens. This is not the first patent we feature today.

Canon patent application 2022-29115 (Japan) discusses optical formulas for a RF 80-240mm f/3.5 zoom lens.

PROBLEM TO BE SOLVED: To provide a compact and lightweight zoom lens having high optical performance in the entire zoom and the entire focus range, and an image pickup device and an image pickup system having the same.

In recent years, the image pickup device has been miniaturized, and the image pickup device used in the image pickup device has a high pixel count. Further, the optical system used in the image pickup apparatus is required to have high optical performance, and to be compact and lightweight. In order to satisfy these requirements, a zoom with positive, negative, positive, positive, and negative refractive power first to fifth lens groups arranged in order from the object side to the image side to reduce various aberrations. A lens has been proposed (see Patent Document 1).

In order to reduce the size of the zoom lens, it is effective to adopt a telephoto type power arrangement and increase the positive refractive power on the object side and the negative refractive power on the image side. However, if the refractive power of each lens group is increased, the fluctuations of various aberrations due to zooming and focusing become large, and it becomes difficult to satisfactorily correct the various aberrations with a limited number of lenses. Therefore, in order to achieve both the optical performance of the zoom lens and the miniaturization, it is important to appropriately set the refractive power of each lens group, the lens configuration, and the position of the focus group.

An object of the present invention is to provide a compact and lightweight zoom lens having high optical performance in the entire zoom and the entire focus range, and an image pickup apparatus and an image pickup system having the same.

Example 1

  • Focal length: 72.00-194.00
  • F value: 2.92
  • Half angle of view: 16.72-6.36
  • Image height: 21.64
  • Overall length: 185.00-255.23
  • Back focus: 16.68-70.96

Example 2

  • Focal length: 72.00-194.00
  • F value: 3.5
  • Half angle of view: 16.72-6.36
  • Image height: 21.64
  • Overall length: 185.00-255.16
  • Back focus: 15.63-65.11

Example 3

  • Focal length: 80.29-232.85
  • F value: 3.5
  • Half angle of view: 15.08-5.31
  • Image height: 21.64
  • Overall length: 222.75-325.37
  • Back focus: 11.49-64.12

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

[via asobinet]